An image forming apparatus is configured such that, a recording sheet such as a sheet or the like is fed to an image forming unit from a multi-purpose sheet feed tray (hereinafter, referred to as MP tray), such as a manual tray or the like, in addition to a sheet feed tray (sheet feed cassette) mounted in a housing.
The image forming apparatus is provided with a sheet feed mechanism configured to separate and feed a plurality of sheets placed in the MP tray one by one to the image forming unit. Specifically, the sheet feed mechanism includes a sheet feed roller configured to rotate while pressing the sheet, a separation pad configured to contact the sheet from a side opposite to the sheet feed roller, and the like.
In the sheet feed mechanism, a plurality of stacked sheets are pressed by the sheet feed roller toward the separation pad, and friction occurs between the separation pad and sheets in contact with the separation pad, so that only a sheet in contact with the sheet feed roller can be fed.
In this sheet feed mechanism, if a support frame supporting the separation pad is bent greatly due to a pressing force of the sheet feed roller which presses the sheets toward the separation pad, an actual pressing force decreases, and a friction which is occurring between the sheets and the separation pad decreases. In this case, a function (hereinafter, referred to as separation and feed function) to separate and feed a plurality of sheets placed in the MP tray one by one to the image forming unit would deteriorate.
If the support frame is formed of resin, the separation and feed function would remarkably deteriorate. This problem can be solved by using resin having high mechanical strength, but the use of such resin having high mechanical strength causes an increase in manufacturing cost of the support frame (image forming apparatus).